ABSTRACT
The idea of reserve against brain damage stems from the repeated observation that there does not appear to be a direct relationship between the degree of brain pathology or brain damage and the clinical manifestation of that damage. For example, Katzman et al. (1989) described 10 cases of cognitively normal elders who were discovered to have advanced Alzheimer’s disease (AD) pathology in their brains at death. They speculated these women did not express the clinical features of AD because their brains were larger than average. Similarly, most clinicians are aware of the fact that a stroke of a given magnitude can produce profound impairment in one patient and while having minimal effect on another. Something must account for the disjunction between the degree of brain damage and its outcome, and the concept of reserve has been proposed to serve this purpose.
